Herbicidal compositions and method



United States Patent 2 993 777 HERBICIDAL coMi os-rrioNs AND METHOD Karl-Heinz Mittelberger, Erich Hambsch, and Heribert Hahne, all of Gersthofen, near Augsburg, Germany,

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In carrying out the invention, said salts may be dissolved in water as a carrier to produce a product adapted for spraying which product contains 1 to 5% of a salt of monochloracetic acid and 0.1 to 0.5% of a salt-of assignors to Farbwerke Hoechst Aktlengesellschaft 5 .pentachlorobutadienoic acid along with a metal of the vor nals Meister Lucius & Briining, Frankfurt am group consisting of alkali and alkaline-earth metals. The fi yi corporation of Germany quantity of the spray product being applied amounts to p f med 3 2, 1959 817,452 100 cc. per square meter or about 1000 liter per hectare Clams gfi l g g 1957 (2.471 acres). The herbicidal compositions may also be alms' 10 incorporated with other carriers such as wetting agents This invention relates to herbicidal compositions and or they may be mixed with inert material to form dusts. more particularly to herbicidal compositions containing The following examples which are by way of illustrasalts of pentachlorobutadienoic acid and monochloracetic tion and not of limitation clearly demonstrate the syne racid. This application is a continuation-impart of our gistic elfect and the high degree of selectivity. The plants co-pending application Serial No. 716,281, filed Februused for the tests were, among others, beans (View. faba), ary 20, 1958, now abandoned. since beans are generally recognized test plants for the It is the object of the present invention to provide an g p f dicotyledo as y record y 'actlon 0f effective means for the selective combatting of dicotyleherbicides, even that of very small amounts, by producdonous weeds. It is a further object of the present ining marked symptoms. vention to provide a better development of useful Example 1 gramineae by destroying dicotyledonous weeds. It is a a further object of the present invention to apply said In greenhollse fab) w t herbicidal compositions by spraying and dusting. y after sowlng with q f Solutlons of calclum A fu the object f the Present invention is the SYnermonochloracetate and the calcium salt of pentacbloro= gistic efiect exerted by the combination of salts of pentab for compfmson wlth a 50mm of chlorobutadienoic acid with monoohloracetic acid. Y the f of these 'actlve substanoes' All the The herbicidal action of the salts of pentachlorob'utaspray hquors were applied at a rate of 1100 Per square dienoic acid (Steinmetz, US. Patent 2,789,044) and'of meterthe monochloracetic acid (Swezey, US. Patent 2,649,363) T e w f damage to the Plants are expressed by is known. In practice, however, both types of comthe folkmmg numbers: .n pouiids failed to attain mportance. Although they'were N0 influence W V V, .Q. H repeatedly applied experimentally for combatting dicotyle- 1 I.

A trace of damage 7'1 donous weeds in agricultural and horticultural planta- Slight damage 9 they l? il e? l and l Damage insuflicient to kill the plant, but growth damage to the plants because of their insutncient selectivity. markedly checked s 3 of i zg fi also ussm'table for Considerable injury which will probably kill the plant 4 com mg we 5 m a etause they Total destruction, the plant was killed 5 damaged the cereals even when they were applied at such small rates which were not sufiicient for killing the weeds. 40 The results given in the following table show that .the

Now, we have found that .the alkali metal and alkalinesynergistic action of the mixture killed the beans.

t lalclum mono- Calcium mono- Calcium salt of chloracetate-l- Active substance chloracetate pentachlorocalcium salt of butadienoic acid pentachlorobutadlenoic acid per ent-.. 2.0 3.0 4.0 0.2 0.5 1.0 2.0+ 0.1 3.0+0.1

V "Afterjtlays r 0 9 0 0 9 0 9 7 Degree of damage to beans- 1 2 2 1 2 4 6 5 earth-metal salts of pentachlorobutadienoic acid, 1,2,3,4,4- Example n pentachlorobutadien- 1,3 )-oic-( 1 acid;

- -|A mixture of seeds of oats (A-vena sativa), wheat (Triticum sativum), barley (Hordeum satz'vum), a mixture of grasses that thrive in the shade, and cleavers (Galium aparine) was sown in beds 1 square meter in area in a vegetation hall, and 6 weeks later the beds were sprayed with aqueous solutions of calcium monochloracetate and of the calcium salt of pentachlorobutadienoic acid, and, for comparison, with a solution of the mixture of these two substances; the solutions were applied at the rate of cc. per square meter.

The results given in the following table show that the mixture had a synergistic action and an excellent selectivity in destroying the Galium aparine without afiecting V the gramineae.

Oelclum mono- Oalcium mono- Calcium salt of chloracetate-l- Active substance chloracetate pentachlorobutacalcium salt of dienoie acid pentachiorobutadienoic acid Percent 2.0 2.5 0.1 0.2 2.0+0.1 2.0+0.2

After days 7 14 7 14 7 14 7 14 7 14 7 14 Degree of damage t Galium aparine 2 2 2 3 1 2 2 2. 3 5 4 5 Gramineae 0 0 0 0 0 0 0 0 0 0 0 0 Example 3 We claim:

Open land lots sown with barley (Hordeum sativum) and heavily infested with hennep nettle (Galeopsis tetrahit) and cleavers (Ga lium aparine) were sprayed with aqueous solutions of the calcium salt of monochloracetic acid and that of the pentachlorobutadienoic acid, and, for comparison, with a solution of the mixture of these two active substances. The liquors were appliedat a rate of 1000 liters per hectare. The spraying was carried out in sunny weather by means of a portable sprayer with a medium size nozzle in repeating each spraying three times.

The results given in the following table show clearly the synergistic action of the calcium salt:

Open land lots of 4 square meters in area, planted with seed potatoes were sprayed in mid-August with aqueous solutions of the sodium salt of monochloracetic acid and that of pentachlorobutadienoic acid, with the addition of each time 0.02% of an alkylnaphthylsulfonate as wetting agent, and, for comparison, with a solution of a mixture of these two active substances.

1. A herbicidal composition consisting essentially of 0.1 to 0.5 by weight of a salt formed of pentachlorobutadienoic acid with a metal of the group consisting of alkali metal and alkaline-earth metals, 1 to 5% by weight of a salt formed of monochloroacetic acid with a metal of the group consisting of alkali metal and alkaline-earth metals, and a carrier, the application rate of said composition in aqueous form being 100 cc. per. square meter of area.

'2. The herbicidal composition of claim 1 wherein the ratio of the salt of pentachlorobutadienoic acid to the salt of monochloracetic acid is about l:-l0 to 1:20 parts by weight.

3. A method for selectively destroying dicotyledonous weeds which comprises spraying on said weeds an aqueous solution of a herbicidal composition consisting essentially The following table gives the results:

7 Sodium monochlor- Sodium Sodium salt acetate-k... Active substance monochlorof pentasodium salt acetate chlorobutaof pentadienoic acid chlorobutadienoic acid,

Percent 5.0 0.5 5.0+0.5

After days 3 5 8 3 5 3 5 8 Degree of damage to: Weed of Solanum tuberosum 1 '2 2 1 2 3 4 5 of a salt of pentachlorobutadienoic acid 01 C1 Cl 01 =C- COOH) References Cited in the file of this patent UNITED STATES PATENTS 2,622,974 Swezey Dec. 23, 1 952 2,622,975 Zimmerman et a1. Dec. 23, 1952 2,549,363 Swezey Aug. 18, 1953 -.2,789,044 Steinmetz Apr. 1 6, 1957 

1. A HERBICIDAL COMPOSITION CONSISTING ESSENTIALLY OF 0.1 TO 0.5% BY WEIGHT OF A SALT FORMED OF PENTACHLOROBUTADIENOIC ACID 